Saw frame structure for releasably holding and tensioning saw blades



' M. S. SWANSTROM SAW FRAME STRUCTURE FOR RELEASABLY HOLDING ANDTENSIONING SAW BLADES July 14. 1953 Filed Au 4, 1950 2 Shots-Sheet i R kmmvrow 3y: ATTORNEYS.

y 4, 1953 M. s. SWANSTRO M 2,645,261

SAW FRAME STRUCTURE FOR RELEASABLY 4 HOLDING AND TENSIONING SAW BLADESFiled Aug. 4, 1950 I |L Huh. Huh."

2 s haots-sheo i- 2 mmvrom ATTORNEYS.

Patented July 14, 1953 UNITED STATES PATENT OFFICE SAW FRAME STRUCTUREFOR RELEASABLY HOLDING AND TENSIONIN G SAW BLADES Martin S. Swanstrom,Chicago, Ill. Application August 4, 1950, Serial No. 177,730

1' This invention relates to a saw, and more particularly to a sawstructure inwhich the blade may be removed and blades of differentlengths may be readily supported therein.

An object of the invention is to provide a saw 7 to provide a sawstructure in which a straight or uncut bar or rail may be employed-as asupport while at the same time providing means for clamping the sawblade in taut condition by a simple movement of a clamp arm. Yet anotherobject is to provide in such a saw structure an end-piece releasablyreceiving rails of different lengths while providing means for securingthe blade against turning movementor distortion. A still further objectis to provide a saw frame structure adapted to support the saw blade indiiferent planes while providing single means for retaining the blade ineither of the planes in which it is secured. Other specific objects andadvantages will appear as ceeds. I

The invention is shown, in illustrative embodiments, by the accompanyingdrawings, in which- Figure l is a side view in elevation of a sawstructure embodying my invention; Fig. 2, a sectional detail view, thesection being taken as indicated at line 2-2 of Fig. 1; Fig. 3, a brokenview in elevation, a portion of the structure being shown in section;Fig. 4, a transverse sectionalview on an enlarged scale, the sectionbeing taken as indicated at line: 44 of Fig. 1; Fig. 5, .a side View inelevation of a modified structure in which the sawblade may be supportedin different planes and with a retainer .for supporting the bladeineither. position; Fig.

6, a side view in elevation of a modified form of the structureembodying my invention; Fig. 7, a

the specification pro- 3 Claims. (01.145 34) I In the illustration givenin Figs. 1 to 4 inclusive, I. provide a handle In, to which there isrigidly secured a depending frame bar II. .The handle 10 is provided atits top with a longitudinally-extending slot I2. A pivot pin 13 extendsthrough the sides of the handle and through the upper portion of theslot and carries a clamping member [4. The depending bar H is preferablyanchored within a ring member [[5 which extends about the forward end ofthe handle l0 and has depending legs. [6 receiving the bar I l.

A saw rail support I! is slidably received withinthe longitudinal slotof the handle and in a position to rock therein,.as illustrated in Fig.3. 'Ihelower edge .of the rail I'l is adapted to rock upon the forwardedge portion l8 of the handle when the rear end of thelrail I1 isdepressed by the clamping member I4, lower end. a

The rail I! may be provided with a plurality of permanent or removablepins 19, which are secured to the lower end of the rail I1 and whichhaving an enlarged serve to lock the rail against rearward movement Iwhen in engagement with the handle portion l8.

The forward end. of the rail IT is provided with a pin 20 adapted toreceive the opening in the upper end of the saw blade 2|.

The bar II is provided at its lower end with a pin or stud 22 adapted toengage an opening in the lower end of the saw blade 2].

Above the pin 22 I prefer to equip the bar H with a stud 23 having acircumferential groove receiving the keeper or retainer 24. The retainer24 is preferably provided with a hook-like lower end 25 which has. aninner side abutting the upper end of the saw blade 21, as illustrated inFigs. 1 and 2, and which thus serves to maintain the blade in a flatcondition, and thus against distortion, when great pressure is placedupon the blade to draw it taut. M

In the operation of the structure shown in Figs. 1 to 4, inclusive, therail I1 is placed in position, as illustratedin Fig. 3, the two ends oftheblade 21 are brought into interlocking engagement with the pins 20and 22, and then the keeper 2.4 is swung to the locking position shownin Figs. 1 ancl 2. If desired, the keeper may be swung in the oppositedirection so that the lower end thereof engages the blade 21 at a pointon the upper side of the pin 22. In either position, the keeper gripsthe flat blade and maintains it in a flattened condition against the barII so that no distortion or twisting thereof occurs when the blade isdrawn to a highly taut condition.

In the structure shown'in Fig. 5, the rail I1 is the same as the railshown in Figs. 1 to 4, in

3 elusive, but the end of the rail is. received within a flattened tube26, the tube 26 having its closed end welded to a depending bar 21. Thebar 21 is provided at its lower end with a pin 28 and with a 7 secondpin 29 carried by a bottom flange 30 which inclusive. The keeper 24 isprovided with a hori zontally-extending foot 33 which extends over andlocks the saw blade 2| when it -is supported in a horizontal positiononthe flanges 3 and 3! and has its end openings in engagement withthepins 29 and 32. Thus the keeper 24 maintains the saw blade, when in saidhorizontal position, in a flat condition against the flanges and 3!.Similarly, when the blade is mounted in a, vertical position with itsend openings receiving the pins 28 and 22, the flat side of the keeperis effective in maintaining the blade against distortion when the clampi4 is moved to locking position.

In the structure shown in Figs. 6 to 8, inclusive,'I provide means foremploying a single plane rail 34 having no pins or indentations therein.The rail may consist of a single plane shaft having no irregularitiestherein, and the shaft may be cut to any desired length or lengths.

The handle 35 is provided with a longitudinal slot for receiving therail 34 and also with arecess, for receivingthe depending bar 36, andthe upper end of the bar may be spot welded at 3'! I within the recessof the handle. The handle is preferably provided'with a raised portionat 38 and a pin 39 is extended through the spaced walls and carries thepresser member 40. The presser member 40 is provided with extensions 4|and with a rearwardly-extending loop handle portion.

'I extend a loop member 42 around the rail 34 and clamp it securely tothe rail by a bolt 43, as shown more clearly in Fig. 8'. By swinging thepresser member 46' from the vertical position shown in Fig. '7 to thehorizontal position shown in Fig. 6, the rail 34 is thrust outwardly forexerting tension upon the saw blade 44.

The depending bar 36- is provided at its lower end with a pin 45 forreceiving the opening at the lower end of the blade 44 and a keeper 24is employed for maintaining the blade in a flat condition when tensionis exerted thereon.

At the outer .end of the rail 34 I provide an end-piece 46 having asocket receiving the forward end of the rail 34 and having apin41extending laterally from itsforward'endi Ialso provide a guard 48which is adapted to hold the upper end of the blade flat against theopposite wall of the end-piece 46, as illustratedin Fig. 6.

In the operation of the structure shown in Figs. 6 to 9, inclusive, Iinsert a rail 34 through the longitudinal slot of the, handle andbetween'the raised side portions 38. of the handle. 'The U- shapedmember 4-2 is clamped in the desired position upon the rail 34 and thesaw blade 44 is placed in position, as illustrated in Fig. 6. The keeper24 is swung downwardly to secure the flattened end of the saw bladeagainst the bar 36, and then the vertical handle 40, as shown in Fig. 7,is swung to the clamping position shown in Fig. 6'. Thepresserextensions 4| of the lever 40 press the member 42 outwardly toplace the blade 44 under great tension. .Dueto the guard 43 and 4. thekeeper member 24 which maintain the blade flat against the innersupporting walls, no distortion of the blade occurs under the heavyclamping force imposed.

For release of the blade, the lever 40 may be swung to the verticalposition shown and the keeper 24 may be swung to the position shown inFig. '7. The blade may then be removed and a longer or shorter bladesubstituted. Since the rail 34 is a plane rail, any desired length maybe I used and any length of saw blade may b thus employed. If it isdesired to use the saw blade in a horizontal'position, an end-piece suchas the end-piece 26 (Fig. 5) may be employed. Similarly, asshown in Fig.5, the blade may be supported in a horizontal or vertical position, asdesired.

In Fig. 10, the bar H is provided with pins 22 and 32 pressed from thebar 1 l and integral with the bar I l 7 The saw structures illustratedrequire a mini- 7 mum of effort in the operation of them because theclamping member may be swun quickly to 7' release or looking positionsand similarly the end-pieces and keeper members are readilymanipulatable to secure saws of any lengths thereon and in differentdesired positions.

While, in the foregoing specification, I have set forth specificstructures in considerable detail for the purpose of illustrating myinvention, it will be understood that such details of structure may bevaried widely by those skilled in the art without departing from thespirit of my invention.

I claim: i 1

1. A saw frame structure for releasably holdin and tensioning a sawblade, comprising a handle having a forwardly-extending upper portionslotted to receive a rail, a plane rail mounted in said slot and movablelongitudinally of said handle, an end-piece having a socket receivingthe outer end of said rail, a pin carried by said end-piece, a dependingbar carried by the forward end of said handle, a pin carried by thelower end of said bar, an abutment member releasably secured to'saidrail, and a presser member having an intermediate portion thereofsupported by a pivot upon said handle, whereby upon the movement of thepresser member from vertical position to horizontal position, theforward portions thereof are pressed against said abutmentmember to moveit outwardly for tensioning said saw blade.

2. A saw frame structure for releasably holding and tensioning a sawblade, comprising a handle having a forwardly-extending upper portionslotted to receive a rail, a plane rail mounted in said slot and movablelongitudinally of said handle, an end-piece having a socket receivingthe outer end of said railfa pin carried by said end-piece, a dependingbar carried by the forward end of said handle, a pin carried b'y thelower end of said bar, an abutment member releasably secured to saidrail, and a pressermember having an intermediate portion thereofsupported by a'pivot upon said handle, whereby upon the movement of thepresser member from vertical position to horizontal position,the'forward portions thereof are pressed against said'abutment member tomove it outwardly for tensioning said saw blade, said end-piece havingalso a guard portion spaced from the pin supporting portion of'saidend-piece and for receiving the saw blade therebetween.

3. frame structure for releasably holding 5 v and tensioning a sawblade, comprising a handl having a forwardly-extending portion providedwith a longitudinal slot, a rail slidably mounted in said slot, anabutment member releasably clamped to said rail, a presser member'pivotally 5 mounted upon said handle and having an extension engageablewith said abutment member to move said rail outwardly from said handle,an end-piece having a slot receiving the forward end of said rail, a pincarried by the outer end of said end-piece for engaging an opening in anend of said saw blade, a depending bar secured to the forward portion ofsaid handle, a pin carried by the lower end of said bar for engaging anopening in the other end of said saw blade, and a keeper memberpivotally mounted upon said depending bar and swingable into engagementwith the adjacent end of said saw blade to hold it in fiat conditionagainst said bar, when the opening in said adjacent end of said sawblade is received 20 References Cited in the file of this patent UNITEDSTATES PATENTS 7 Number Number Name Date Fornander Nov. 10, 1885Hathaway May 15, 1888 Saxton June 5, 1900 Martin July 15, 1902 TildenMar. 24, 1914 Siddon Feb. 14, 1922 Remington Aug. 1, 1922 DonaldsonSept. 12, 1922 FOREIGN PATENTS Country Date France Oct. 28, 1922 FranceJuly 22, 1924 Australia Sept. 25, 1947

